High-strength impermeability concrete and preparation method thereof

Abstract

The present invention discloses a high-strength impermeable concrete, which is made from the following raw materials in parts by weight: 200-260 parts of cement, 100-140 parts of coarse aggregate, 200-220 parts of fine aggregate, 60-100 parts of fly ash, 20-30 parts of fiber reinforcement, 10-20 parts of impermeability agent, 3-5 parts of water reducer, and 100-120 parts of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:2-4:0.5-0.8. The obtained concrete has a better internal microstructure, good density, excellent compressive and splitting tensile strength, and impermeability, good overall performance, and good market application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete, and particularly relates to high-strength anti-permeability concrete and a preparation method thereof. Background Art

[0002] In recent years, my country's construction industry has experienced rapid development. However, ordinary cement concrete suffers from shortcomings such as poor toughness, durability, crack resistance, and brittleness, making it difficult to meet the durability and high strength requirements of modern construction projects. Consequently, as building performance requirements for concrete increase, high-strength concrete has become the epitome of modern concrete technology and the future direction of development. However, high-strength concrete also suffers from the disadvantages of high brittleness, low tensile strength, and poor crack resistance. High-strength concrete contains numerous unhydrated cement particles, comprising approximately 40% to 70% of the total cement content. When high-strength concrete absorbs water in a humid environment, the unhydrated cement within it continues to hydrate, generating hydration products with a volume significantly larger than the original cement, gradually filling the concrete's internal pores. If this reaction continues, the volume of the cement hydration products will exceed the volume of the concrete's internal pores, generating expansion stresses within the concrete, leading to numerous microcracks, a decrease in strength, and poor impermeability. Therefore, improving concrete's impermeability and strength is of great significance. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-strength impermeability concrete, which has the advantages of high strength, good impermeability and long service life, and can better meet the needs of modern concrete engineering.

[0004] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0005] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 200-260 parts of cement, 100-140 parts of coarse aggregate, 200-220 parts of fine aggregate, 60-100 parts of fly ash, 20-30 parts of fiber reinforcement, 10-20 parts of impermeability agent, 3-5 parts of water reducer, and 100-120 parts of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:2-4:0.5-0.8.

[0006] Preferably, the modified sepiolite fiber is prepared by the following method:

[0007] (1) Graphene oxide powder and nano-silica powder were mixed uniformly in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 min. Aniline and ammonium persulfate were then added thereto. The mixture was stirred and reacted at room temperature for 24 h. The reaction product was centrifuged and the obtained solid product was washed three times with deionized water and anhydrous ethanol, respectively, and dried to obtain a solid material A.

[0008] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber;

[0009] (3) Solid material A and amino-modified sepiolite fiber were mixed according to the mass ratio, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonic dispersion of the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0010] Preferably, in step (1), the ratio of the graphene oxide powder to the mixture of nano-silicon dioxide powder, hydrochloric acid solution, aniline, and ammonium persulfate is 5 g:100 ml:0.1-0.15 mol:0.12-0.18 mol.

[0011] Preferably, in step (2), the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 5-8g:200ml:0.5g.

[0012] Preferably, in step (3), the mass ratio of solid matter A to amino-modified sepiolite fiber is 1:4.

[0013] Preferably, the water reducer is a naphthalene-based water reducer or a polycarboxylic acid-based high-efficiency water reducer.

[0014] Preferably, the cement is ordinary Portland cement.

[0015] The present invention also provides a method for preparing the above-mentioned high-strength impermeability concrete, which comprises the following steps:

[0016] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0017] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0018] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0019] In concrete materials, fiber is mixed as reinforcing material to improve the strength, durability, crack resistance and overall performance of concrete, for example, basalt fiber, steel fiber, polyvinyl alcohol fiber etc. can be mixed. Because the fiber of different properties has a greater impact on the performance of concrete after mixing. The present invention adopts the mode of mixing modified sepiolite fiber with polyvinyl alcohol fiber (PVA) to improve the strength and impermeability of concrete, and PVA fiber therein can effectively improve the impermeability of concrete by limiting the expansion of cracks inside concrete; modified sepiolite fiber is the composite material formed by further modification treatment of sepiolite fiber with surface amino modification and silicon dioxide, polyaniline and graphene oxide, wherein the composite material formed by silicon dioxide, polyaniline and graphene oxide is rich in groups such as hydroxyl, carboxyl and epoxy groups, and these groups can form stable combination with the amino groups on the sepiolite surface by electrostatic attraction or covalent bond bonding, enhance interface stability, and show higher interface bonding strength and mechanical property for concrete. At the same time, the addition of modified sepiolite fiber forms a large number of needle-shaped ettringite and flaky calcium hydroxide crystals inside, which effectively improves the density of the mortar hardening system, thereby improving the strength and impermeability of concrete.

[0020] The anti-seepage agent used in the present invention is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in specific proportions. Sodium lignin sulfonate improves the density of concrete through water reduction, the hydrophobicity of tetramethyldivinyldisiloxane further reduces water penetration, and neodymium chloride further enhances the density of concrete by accelerating the cement hydration reaction. The three synergistically enhance the interface bonding between the cement matrix and the aggregate, reduce interfacial defects, and thus improve the overall performance of the concrete. When used in conjunction with the fiber reinforcement prepared by the present invention, the synergistic effect is significant, which can significantly improve the strength, durability, crack resistance and overall performance of the concrete.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) The concrete prepared by mixing a fiber reinforcement made of modified sepiolite fiber and polyvinyl alcohol fiber in proportion with other raw materials has excellent compressive strength, splitting tensile strength and impermeability, good overall performance and good market application prospects.

[0023] 2) Select an appropriate proportion of anti-seepage agent and fiber reinforcement in combination, and the raw materials complement each other to further optimize the internal microstructure of concrete, improve the density of concrete, and further improve the anti-seepage performance of concrete. DETAILED DESCRIPTION

[0024] The technical solutions of the present invention are further described below with reference to specific embodiments, but are not limited thereto. Unless otherwise specified, the raw materials used in the examples of the present invention are commercially available, including PO 42.5 cement, Grade I fly ash, sepiolite fibers with a length of 1-5 mm, and polyvinyl alcohol fibers with a length of 9-12 mm.

[0025] Example 1

[0026] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 240 kg of cement, 120 kg of coarse aggregate, 210 kg of fine aggregate, 80 kg of fly ash, 25 kg of fiber reinforcement, 15 kg of impermeability agent, 4 kg of water reducer, and 110 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:2:0.5.

[0027] The modified sepiolite fiber is prepared by the following method:

[0028] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.1mol:0.12mol;

[0029] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65°C for reaction for 2-3 hours, filtering to obtain the treated solid fiber after the reaction, washing with deionized water for more than 3 times, and drying to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 5g:200ml:0.5g;

[0030] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:4, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0031] The water reducer is a naphthalene-based water reducer; and the cement is ordinary Portland cement PO 42.5.

[0032] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0033] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0034] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0035] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0036] Example 2

[0037] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 200 kg of cement, 100 kg of coarse aggregate, 200 kg of fine aggregate, 60 kg of fly ash, 20 kg of fiber reinforcement, 10 kg of impermeability agent, 3 kg of water reducer, and 100 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:4:0.8.

[0038] The modified sepiolite fiber is prepared by the following method:

[0039] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain a solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.15mol:0.18mol;

[0040] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65°C for reaction for 2-3 hours, filtering to obtain the treated solid fiber after the reaction, washing with deionized water for more than 3 times, and drying to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 8g:200ml:0.5g;

[0041] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:4, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0042] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0043] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0044] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0045] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0046] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0047] Example 3

[0048] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 20 kg of impermeability agent, 5 kg of water reducer, and 120 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:3:0.6.

[0049] The modified sepiolite fiber is prepared by the following method:

[0050] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.12mol:0.16mol;

[0051] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 6 g:200 ml:0.5 g;

[0052] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:4, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0053] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0054] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0055] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0056] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0057] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0058] Comparative Example 1

[0059] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 20 kg of impermeability agent, 5 kg of water reducer, and 120 kg of water; the fiber reinforcement is composed of sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:3:0.6.

[0060] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0061] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0062] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0063] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0064] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0065] The comparative example is basically the same as Example 3, except that the fiber reinforcement is composed of unmodified sepiolite fiber and polyvinyl alcohol fiber.

[0066] Comparative Example 2

[0067] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 20 kg of impermeability agent, 5 kg of water reducer, and 120 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:3:0.6.

[0068] The modified sepiolite fiber is prepared by the following method:

[0069] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.12mol:0.16mol;

[0070] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 6 g:200 ml:0.5 g;

[0071] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 2:1, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0072] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0073] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0074] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0075] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0076] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0077] The comparative example is basically the same as Example 3, except that the modified sepiolite fiber is prepared by mixing solid material A and amino-modified sepiolite fiber in a mass ratio of 2:1.

[0078] Comparative Example 3

[0079] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 20 kg of impermeability agent, 5 kg of water reducer, and 120 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:3:0.6.

[0080] The modified sepiolite fiber is prepared by the following method:

[0081] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.12mol:0.16mol;

[0082] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 6 g:200 ml:0.5 g;

[0083] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:1, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0084] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0085] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0086] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0087] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0088] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0089] The comparative example is basically the same as Example 3, except that the modified sepiolite fiber is prepared by mixing solid material A and amino-modified sepiolite fiber in a mass ratio of 1:1.

[0090] Comparative Example 4

[0091] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 20 kg of impermeability agent, 5 kg of water reducer, and 120 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:3:0.6.

[0092] The modified sepiolite fiber is prepared by the following method:

[0093] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.12mol:0.16mol;

[0094] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 6 g:200 ml:0.5 g;

[0095] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:2, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0096] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0097] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0098] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0099] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0100] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0101] The comparative example is basically the same as Example 3, except that the modified sepiolite fiber is prepared by mixing solid material A and amino-modified sepiolite fiber in a mass ratio of 1:2.

[0102] Comparative Example 5

[0103] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 20 kg of impermeability agent, 5 kg of water reducer, and 120 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:3:0.6.

[0104] The modified sepiolite fiber is prepared by the following method:

[0105] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.12mol:0.16mol;

[0106] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 6 g:200 ml:0.5 g;

[0107] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:6, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0108] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0109] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0110] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0111] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0112] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0113] The comparative example is basically the same as Example 3, except that the modified sepiolite fiber is prepared by mixing solid material A and amino-modified sepiolite fiber in a mass ratio of 1:6.

[0114] Comparative Example 6

[0115] A high-strength, impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 5 kg of water reducer, and 120 kg of water. The fiber reinforcement is a mixture of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1. The modified sepiolite fiber is prepared by the following method:

[0116] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.12mol:0.16mol;

[0117] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 6 g:200 ml:0.5 g;

[0118] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:4, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0119] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0120] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0121] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0122] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0123] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0124] The above comparative example is basically the same as Example 3, except that it does not contain an anti-seepage agent.

[0125] Comparative Example 7

[0126] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 20 kg of impermeability agent, 5 kg of water reducer, and 120 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate and tetramethyldivinyldisiloxane in a mass ratio of 1:3.

[0127] The modified sepiolite fiber is prepared by the following method:

[0128] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.12mol:0.16mol;

[0129] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 6 g:200 ml:0.5 g;

[0130] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:4, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0131] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0132] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0133] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0134] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0135] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0136] The above comparative example is basically the same as Example 3, except that the anti-seepage agent does not contain neodymium chloride.

[0137] Comparative Example 8

[0138] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 20 kg of impermeability agent, 5 kg of water reducer, and 120 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of sodium lignin sulfonate and neodymium chloride in a mass ratio of 1:0.6.

[0139] The modified sepiolite fiber is prepared by the following method:

[0140] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.12mol:0.16mol;

[0141] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 6 g:200 ml:0.5 g;

[0142] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:4, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0143] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0144] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0145] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0146] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0147] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0148] The comparative example is substantially the same as Example 3, except that the anti-seepage agent does not contain tetramethyldivinyldisiloxane.

[0149] Comparative Example 9

[0150] A high-strength impermeable concrete is made from the following raw materials in parts by weight: 260 kg of cement, 140 kg of coarse aggregate, 220 kg of fine aggregate, 100 kg of fly ash, 30 kg of fiber reinforcement, 20 kg of impermeability agent, 5 kg of water reducer, and 120 kg of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the impermeability agent is composed of tetramethyldivinyldisiloxane and neodymium chloride in a mass ratio of 1:3:0.6.

[0151] The modified sepiolite fiber is prepared by the following method:

[0152] (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 minutes. Aniline and ammonium persulfate were then added thereto, and the mixture was stirred and reacted at room temperature for 24 hours. The reaction product was centrifuged, and the obtained solid product was washed with deionized water and anhydrous ethanol three times, respectively, and dried to obtain solid material A; wherein the amount ratio of the mixture of graphene oxide powder and nano-silica powder, hydrochloric acid solution, aniline, and ammonium persulfate was 5g:100ml:0.12mol:0.16mol;

[0153] (2) Adding sepiolite fiber to a 0.2 mol / L ethylenediamine solution, adding aluminum chloride, stirring evenly, heating the mixture to 60-65° C. and reacting for 2-3 hours. After the reaction is completed, filtering to obtain the treated solid fiber, washing it with deionized water for more than 3 times, and drying it to obtain amino-modified sepiolite fiber; wherein the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 6 g:200 ml:0.5 g;

[0154] (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:4, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

[0155] The water reducer is a polycarboxylate water reducer; and the cement is ordinary Portland cement PO 42.5.

[0156] The preparation method of the above-mentioned high-strength impermeability concrete comprises the following steps:

[0157] S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix;

[0158] S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry;

[0159] S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.

[0160] The comparative example is basically the same as Example 3, except that the anti-seepage agent does not contain sodium lignin sulfonate.

[0161] Performance Testing

[0162] The high-strength, impermeable concrete of Examples 1-3 and Comparative Examples 1-9 was poured into a test mold measuring 100 mm × 100 mm × 100 mm. The samples were demolded 24 hours after molding and then placed in a standard curing chamber at a temperature of (20±2)°C and a relative humidity of >95% for 28 days. Mechanical properties, including compression and splitting tensile strength tests, were measured according to the national standard GB / T 50081-2002, "Standard for Test Methods for Mechanical Properties of Ordinary Concrete." Impermeability was measured according to the national standard GB / T 50082-2009, "Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete." The sample size was adjusted to a penetration pressure of 1 MPa for 48 hours. The specific test results are shown in Table 1.

[0163] Table 1 Test results

[0164] Compressive strength (MPa) Splitting tensile strength (MPa) Water seepage height (mm) Example 1 68.6 6.95 0.25 Example 2 65.9 6.89 0.19 Example 3 67.5 6.77 0.23 Comparative Example 1 55.6 5.09 1.68 Comparative Example 2 52.9 5.02 2.01 Comparative Example 3 55.9 5.53 0.53 Comparative Example 4 60.5 5.92 0.35 Comparative Example 5 58.9 5.47 0.32 Comparative Example 6 53.1 5.06 1.99 Comparative Example 7 59.5 5.98 1.12 Comparative Example 8 60.2 6.12 0.89 Comparative Example 9 58.7 6.06 1.22

[0165] As can be seen from the data in Table 1 above, the compressive strength, splitting tensile strength and impermeability of the concrete prepared in Examples 1-3 of the present invention are all superior to those in Comparative Examples 1-9. As can be seen from the data in Comparative Examples 1-5, the addition of modified sepiolite fiber to the concrete of the present invention can improve the mechanical properties of the concrete compared with Comparative Example 1 of unmodified sepiolite fiber. However, as can be seen from the data in Comparative Examples 2-5, the modification method of the modified sepiolite fiber has a greater impact on the performance of the concrete. When the amount of solid material A and the amino-modified sepiolite fiber is too much, the concrete performance is reduced. This is because the excessive graphene oxide and silicon dioxide in the concrete are easily agglomerated. This agglomeration phenomenon reduces the dispersibility of the material, resulting in an uneven internal structure of the concrete, thereby reducing performance. In addition, excessive use also leads to increased costs. When the amount of solid material A is too little, it cannot play a good synergistic role with the amino-modified sepiolite fiber to achieve a good effect of enhancing interface stability and improving the interface bonding strength and mechanical properties of the concrete. It can be seen from the results of Comparative Examples 6-9 that changing the composition of the anti-seepage agent will correspondingly weaken the mechanical properties of the concrete. This shows that the raw materials constituting the anti-seepage agent of the present invention complement each other and are indispensable. They work together with the fiber reinforcement and other raw materials to prepare a high-strength anti-seepage concrete with broad market application prospects.

[0166] It should be noted that the above embodiments are only some of the preferred embodiments of the present invention, and not all of them. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

Claims

1. A high-strength and impermeable concrete, characterized in that: It is made of the following raw materials in parts by weight: 200-260 parts of cement, 100-140 parts of coarse aggregate, 200-220 parts of fine aggregate, 60-100 parts of fly ash, 20-30 parts of fiber reinforcement, 10-20 parts of anti-seepage agent, 3-5 parts of water reducer, and 100-120 parts of water; the fiber reinforcement is composed of modified sepiolite fiber and polyvinyl alcohol fiber in a mass ratio of 3:1; the anti-seepage agent is composed of sodium lignin sulfonate, tetramethyldivinyldisiloxane, and neodymium chloride in a mass ratio of 1:2-4:0.5-0.8; The modified sepiolite fiber is prepared by the following method: (1) Graphene oxide powder and nano-silica powder were mixed in a mass ratio of 1:3, added to a 2 mol / L hydrochloric acid solution, and ultrasonically dispersed for 10-15 min. Aniline and ammonium persulfate were then added thereto. The mixture was stirred and reacted at room temperature for 24 h. The reaction product was centrifuged and the obtained solid product was washed three times with deionized water and anhydrous ethanol, respectively, and dried to obtain solid material A. (2) Add sepiolite fiber to 0.2 mol / L ethylenediamine solution, add aluminum chloride, stir evenly, heat the mixture to 60-65 ° C and react for 2-3 hours. After the reaction is completed, filter to obtain the treated solid fiber, wash it with deionized water for more than 3 times, and dry it to obtain amino-modified sepiolite fiber; (3) Solid material A and amino-modified sepiolite fiber were mixed in a mass ratio of 1:4, and then mechanically ground at a speed of 100 r / min for 1 hour. After ultrasonically dispersing the mixture for 30 minutes, the modified sepiolite fiber was obtained.

2. The high-strength impermeable concrete according to claim 1, characterized in that: In step (1), the ratio of the graphene oxide powder and nano-silicon dioxide powder mixture, hydrochloric acid solution, aniline, and ammonium persulfate is 5 g:100 ml:0.1-0.15 mol:0.12-0.18 mol.

3. The high-strength impermeable concrete according to claim 1, characterized in that: In step (2), the mass volume ratio of sepiolite fiber, ethylenediamine solution, and aluminum chloride is 5-8g:200ml:0.5g.

4. The high-strength impermeable concrete according to claim 1, characterized in that: The water reducer is a naphthalene-based water reducer or a polycarboxylic acid-based high-efficiency water reducer.

5. The high-strength impermeable concrete according to claim 1, characterized in that: The cement is ordinary Portland cement.

6. A method for preparing high-strength and impermeable concrete according to any one of claims 1 to 5, characterized in that: It includes the following steps: S1: Mix cement, coarse aggregate and fine aggregate to obtain a premix; S2: adding fly ash and fiber reinforcement to the premix and stirring evenly, and adding water, anti-seepage agent and water reducing agent and continuing to stir and mix evenly to obtain a mixed slurry; S3: The slurry is poured, formed and cured to produce finished high-strength and impermeable concrete.